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MHT CET 2026 (16 Apr, Shift 1) · Electrostatic Potential Energy

Electrostatic Potential Energy question from MHT CET 2026 (16 Apr, Shift 1)

Q12MHT CET 2026 · 16 APR · SHIFT 1Medium

Electrostatic Potential Energy

Two point charges q1=6 μq_1 = 6\,\muC and q2=4 μq_2 = 4\,\muC are kept at points A and B in air where distance AB=10AB = 10 cm. What is the increase in potential energy of the system when q2q_2 is moved towards q1q_1, by 2 cm? (14πϵ0=9×109\Bigg(\frac{1}{4\pi\epsilon_0} = 9 \times 10^{9} SI units)\Bigg)

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Answer: (c)

  1. ΔU=kq1q2(1r2−1r1)\Delta U = kq_1q_2\left(\dfrac{1}{r_2} - \dfrac{1}{r_1}\right) with r1=0.10r_1 = 0.10 m, r2=0.08r_2 = 0.08 m.
  2. kq1q2=9×109×24×10−12=0.216kq_1q_2 = 9\times10^9 \times 24\times10^{-12} = 0.216
  3. ΔU=0.216(12.5−10)=0.54\Delta U = 0.216(12.5 - 10) = 0.54 J
  4. So the answer is (c) 0.54 J.
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